A light source unit and reader can include a line light source that is attached to a radiator and a rod lens that is attached above the line light source. The radiator with the line light source and the rod lens attached thereto, and a linear strip-shaped reflector arranged in front of the rod lens, are housed in a carriage. The carriage is supported beneath a contact glass and movable in a direction normal to a longitudinal axis of the line light source. The lens has a section in a plane normal to a longitudinal axis of the lens, in which a surface of the lens facing the light source has a curved line that expands or is convexly facing toward the light source. The opposite surface of the lens from the light source has composite curves including a plurality of continuous curves with different radii of curvature. The composite curves are located on both sides of a plane containing the optical axis of the LED and expand or are convex in an opposite direction from the light source.
Legal claims defining the scope of protection, as filed with the USPTO.
1. A light source unit configured to apply light to a surface of an object and to receive light reflected from the surface of the object in order to read the object, the light source unit comprising: a line light source having a longitudinal axis; a rod lens having a longitudinal axis substantially in parallel with the longitudinal axis of the line light source, the rod lens having a first optical-axis plane and a second optical-axis plane, the first optical-axis plane containing a plurality of optical axes passing through a first linear line focus group containing a plurality of first focuses, the second optical-axis plane containing a plurality of optical axes passing through a second linear line focus group containing a plurality of second focuses; and a linear reflector located on an opposite side of the rod lens as compared to the line light source and at a position crossing the second optical-axis plane of the rod lens, wherein the first linear line focus group and the second linear line focus group are located substantially at a position where the second optical-axis plane when reflected from the linear reflector crosses the first optical-axis plane.
2. The light source unit according to claim 1 , wherein the first optical-axis plane and the second optical-axis plane when reflected from the linear reflector cross at an angle of 80-100°.
3. The light source unit according to claim 1 , wherein the first linear line focus group is located at a distance of 2-5 mm from the second linear line focus group.
4. The light source unit according to claim 1 , wherein the rod lens has surfaces on a side facing the line light source and an opposite side when sectioned along a plane normal to the longitudinal direction of the rod lens, the surfaces having shapes of composite curves when viewed in section normal to the longitudinal axis of the rod lens and including a plurality of continuous curves with different radii of curvature, the composite curves located on both sides of a third optical axis of the line light source passing through the rod lens, the composites curves being convex and expanding away from the line light source, wherein the composite curves have a link therebetween, which is a straight line in parallel with the third optical axis.
5. The light source unit according to claim 1 , wherein the first optical-axis plane and the second optical-axis plane before reflection from the linear reflector form an angle of 40°.
6. The light source unit according to claim 1 , wherein the line light source includes a plurality of white LEDs that are linearly arrayed.
7. The light source unit according to claim 1 , further comprising an object reader and a contact glass, wherein the line light source is movably attached to the contact glass in a direction normal to the longitudinal direction of the line light source while the first optical-axis plane of the rod lens and the second optical-axis plane after being reflected from the linear reflector are each at an angle of 40-50° with respect to a plane normal to the contact glass.
8. The light source unit according to claim 1 , wherein the light source unit is configured for use in reading documents.
9. A light source unit and reader configured to apply light to a surface of an object and to receive light reflected from the surface of the object in order to read the object, the light source unit and reader comprising: a line light source having a longitudinal axis; a rod lens having a longitudinal axis substantially in parallel with the longitudinal axis of the line light source, and having a first convex curved surface facing away from the line light source and having a first optical-axis, the rod lens having a second convex curved surface separated from the first convex curved surface by at least one of a linear link portion of the rod lens and a concave portion of the rod lens, the second convex curved surface having a second optical-axis, the first convex surface having a first focus, the second convex surface having a second focus; and a reflector having a longitudinal axis and located on an opposite side of the rod lens as compared to the line light source and at a position crossing the second optical-axis of the rod lens, wherein the first focus and the second focus are located substantially at a position where the second optical-axis when reflected from the reflector crosses the first optical-axis.
10. The light source unit and reader according to claim 9 , wherein the first optical-axis and the second optical-axis after being reflected from the reflector cross at an angle of 80-100°.
11. The light source unit and reader according to claim 9 , wherein the first focus is located at a distance of 2-5 mm from the second focus.
12. The light source unit and reader according to claim 9 , wherein the rod lens has a receiving surface on a side facing the line light source and an opposite emitting side surface when sectioned along a plane normal to the longitudinal direction of the rod lens, the emitting side surface includes shapes of composite curves when viewed in section normal to the longitudinal axis of the rod lens, the composite curves including a plurality of continuous curves with different radii of curvature, at least a first of the composite curves being located on a first side of a third optical axis of the line light source which passes through the rod lens, the first of the composite curves being convex and expanding away from the line light source, and at least a second of the composite curves being located on a second side of the third optical axis of the line light source opposite to the first side, the second of the composite curves being convex and expanding away from the line light source, wherein the first and second composite curves have a link surface located therebetween, the link surface being a straight line in parallel with the third optical axis.
13. The light source unit and reader according to claim 9 , wherein the first optical-axis and the second optical-axis form an angle of 40°.
14. The light source unit and reader according to claim 9 , wherein the line light source includes a plurality of white LEDs that are linearly arrayed.
15. The light source unit and reader according to claim 9 , further comprising: an object reader and a contact glass, wherein the line light source is movably attached to the contact glass in a direction normal to the longitudinal direction of the line light source while the first optical-axis of the rod lens and the second optical-axis after being reflected from the linear reflector are each at an angle of 40-50° with respect to a plane normal to the contact glass.
16. The light source unit and reader according to claim 9 , further comprising: a contact glass configured for placement of the object thereon; and a carriage located adjacent and configured to move relative to the contact glass, wherein the line light source, rod lens, and reflector are located in and moveable with the carriage.
Cooperative Patent Classification codes for this invention. Click any code to explore related patents in that topic.
July 23, 2008
October 11, 2011
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